A control board, such as in a controller for an HVAC system, can include multiple components and circuits that are rated to operate at a certain supply voltage or range of supply voltages. Often a control board will include a circuit or circuits that are designed to protect the components and circuits from sudden or momentary overvoltage conditions. One common cause of an overvoltage in circuits is electrostatic discharge (ESD). ESD is the transfer of an electrostatic charge between two objects (e.g., electronic devices) of different electric potential. Electronic devices, such as the controllers, often include overvoltage protection circuits to prevent damage when an overvoltage condition occurs.